Association between Parkinson's Disease and Prostate Cancer

Researchers have found compelling evidence that Parkinson's disease is associated with an increased risk of prostate cancer and melanoma, and that this increased cancer risk also extends to close and distant relatives of individuals with Parkinson's disease.

Although a link between Parkinson's disease and melanoma has been suspected before, this is the first time that an increased risk of prostate cancer has been reported in Parkinson's disease.

Parkinson's disease (PD) is a progressive neurologic condition that leads to tremors and difficulty with walking, movement, and coordination. Most studies demonstrate that individuals with PD have an overall decreased rate of cancer, with the notable exception of melanoma, the most serious form of skin cancer.

Previous research has suggested a possible genetic link between PD and melanoma, but these studies have been limited to first-degree relatives who often share a similar environment, making it difficult to distinguish between genetic and environmental risk factors.

"Neurodegenerative disorders such as Parkinson's disease may share common disease-causing mechanisms with some cancers," says Stefan-M. Pulst at the University of Utah. "Using the Utah Population Database, we were able to explore the association of PD with different types of cancer by studying cancer risk in individuals with PD, as well as their close and distant relatives."

The study team screened the Utah Population Database (UPDB) to identify nearly 3000 individuals with at least three generations of genealogical data who had PD listed as their cause of death. The researchers discovered that the risk of prostate cancer and melanoma within this PD population was significantly higher than expected.

They also observed an increased risk for prostate cancer and melanoma among first-, second-, and third-degree relatives of these individuals with PD, although the excess risk for melanoma in third-degree relatives did not reach statistical significance.

In order to validate the observed association between PD-related death and these two cancers, the researchers also identified individuals who were diagnosed with either melanoma or prostate cancer to evaluate their risk for death with PD. They found that these individuals, as well as all their relatives, had a significantly increased risk for death with PD.

"Our findings point to the existence of underlying pathophysiologic changes that are common to PD, prostate cancer, and melanoma," says Cannon-Albright. "Exploring the precise genetic links among these diseases could improve our understanding of PD and influence strategies for prostate and skin cancer screening."